Question #22549

2 Answers
Dec 20, 2017

Please see the processed steps below;

Explanation:

Probability of #3# posts selected is #3/9 = 1/3#

Probability of none selected is #(9-3)/9 or (1 - 1/3)#

#(9-3)/9#

#6/9#

#2/3#

Hence;

Probability of none selected is #= 2/3#

Jan 2, 2018

#2/3#

Explanation:

#9# applicants , #3# posts
so probability of anyone selected at any post is #3/9=1/3#
so, probability that the same person is not selected can be easily identified
#P(s)+P(n)=1# where #P(s)# means selected and #P(n)# means not selected )
#1/3+P(n)=1#
#P(n)=1-1/3#
#P(n)=(3-1)/3#
#P(n)=2/3#
Cheers!
If the question is that none of them is selected , then we woupd require probability of selection of each which on an average would not be greater than #1/3#.
My interpretion of question is that we need to find the probability of anyone not being selected .

It might require use of linear inequalities if the question isn't what i interpret .

for more please see my hand written script below
self written